An interesting signature of the first-order phase transition is the stochastic gravitational wave (GW) from the collision of the nucleated bubbles. The GW spectrum from the phase transition can be typically characterized by the following parameters, the released latent heat \(\alpha \) , the inverse of the duration of phase transition \(\beta \) , and transition temperature \(T_t\) . These parameters can be determined from the shape of the scalar potential for electroweak symmetry breaking; thus, it is likely that new physics models with first-order phase transition can be explored by GW observations.
In particular, the frequency of the GW spectrum produced by the first-order EWPT is typical \(10^{-3}\) –10 Hz. Such a GW spectrum with sub-Hz frequency should be detected by the space-based interferometers in the future, such as LISA [1]}, DECIGO [2]} and BBO [3]}.
